By way of example, a circuit breaker of the type mentioned initially is known from DE 3341903 A1. The known circuit breaker has switching pieces which move with respect to one another and whose arcing and rated current contacts are moved along a common longitudinal axis of the switch. During the switching-on movement, the moving arcing contact is moved into the stationary arcing contact. All the rated current contacts, which are in the form of fingers, of the moving switching piece are arranged coaxially with respect to and at the same distance from the arcing contact. Some of the rated current contact fingers are positioned in front of the other rated current contact fingers in the direction of the longitudinal axis. During the switching-on movement, the rated current contacts, which are in the form of fingers, move over the opposing rated current contact, which is in the form of a cylindrical switching piece, and the current is first commutated through the already closed arcing contacts onto the leading rated current contact fingers, and then onto the other, shorter rated current contact fingers. The leading rated current contact fingers are designed to be arc-resistant, for this purpose. When the rated current contact system is closing, all the rated current contacts, which are in the form of fingers, exert a mechanical pressure force onto the internal opposing rated current contact piece. The pressure force is additionally reinforced by the electromagnetic force which occurs as a result of the current flow in the rated current contacts. This leads to a high pressure force, and therefore, to a high total friction force between the rated current contacts which are making contact. The friction force must be overcome by the drive during the opening and closing phase of the switch. In this and other switches, the current flowing via the outer rated current contact fingers to the opposing rated current contact causes an electromagnetic force which, in the event of a short-circuit, can exceed the mechanical friction force which occurs on the switch, and can thus complicate or even render impossible the opening and closing movement of the switch.
In this and other circuit breakers, there are limitations on the current carrying capability and the contact characteristics of the rated current contacts of the switch, such as in the event of a short-circuit in the switch, for example.